1. Field of the Invention
The present invention relates to a sorting conveyor arrangement with a plurality of plates or trays which are arranged usually immediately successively in the conveying direction and are tiltable to both sides about a center axis which extends in the same direction as the conveying direction. The tiltable plates or trays are mounted by means of appropriate support members on an endless circulating chain or the like. The tiltable plates or trays are tilted and returned into the original position by means of appropriate control cams, guide tracks, switches, restoring rollers or similar elements.
2. Description of the Related Art
Various embodiments of the above-described type of conveyor arrangements have been known for a long time. They are used, for example, by postal services for sorting parcels and they are also used in mail order businesses or the like.
However, all previously known systems with forced or positive tilting operation, as disclosed, for example, by European Patent No. 0 173 399, have the disadvantage that the roller guides arranged in separate drums on the respective tilting carriages permit for structural reasons only extremely small lever arms of the control members for the roller guides and, thus, relatively great forces occur on the guide elements and significant wear occurs as a result. This inevitably leads after already a short time to rough running of the entire arrangement and to unstable conditions in the tilting carriages both in the basic positions as well as in the tilted positions. Accordingly, arrangements of this known type are not at all suitable for sorting and conveying parcels of higher weights, i.e. parcels having a maximum weight of, for example, 31.5 kilograms, as required today by some postal services. The known arrangement disclosed by European Patent 0 173 399 has the additional disadvantage that the entire arrangement is very expensive because of the structurally complicated construction and configuration of the control curves and the control elements, particularly when considering the fact that the ratio of tilting carriages to tilting stations usually is approximately 10/1.